Elderly people who maintain a modest program of exercise are less likely to take a bad fall than those who do little physical activity. An analysis of 17 trials finds that people assigned to exercise regularly were substantially less likely to break a bone due to falling.

Falling in old age can be a life-changing event. People who fall are often frail to begin with, and an injury can compound their problems. In people over 75, for example, a broken hip worsens a person’s five-year survival odd...